Computerized control of behavioral paradigms is an essential element of neurobehavioral studies, especially physiological recording studies that require sub-millisecond precision. Few software solutions provide a simple, flexible environment to create and run these applications. We report that NIMH MonkeyLogic (formerly MonkeyLogic), a MATLAB-based package, has been redesigned and rewritten to support the latest 64-bit MATLAB on the Windows platform. Major layers of the underlying real-time hardware control were removed and replaced by custom toolboxes: NIMH DAQ Toolbox and MonkeyLogic Graphics Library. The redesign resolves undesirable delays in data transfers and limitations in graphics capabilities. In addition, NIMH MonkeyLogic provides more input device options, superior graphics, and a new real-time closed-loop programming model. Tastes and their associated values drive food consumption and influence choice behavior. To understand the neural mechanisms underlying reward-guided decision making and value learning, we characterized the gustatory system in subjects with fMRI while measuring licking to control for oral movements, and to assess preferences. To identify taste-responsive cortex, we delivered small quantities of sucrose, citric acid, or distilled water in random order without any predictive cues (e.g., visual stimuli) to subjects while using event-related fMRI. In addition, we used an MRI-compatible lick sensor to measure subjects licking during the scans. fMRI signals associated with licking in the absence of fluid delivery were used to mask responses to fluid delivery/receipt and associated licking. Licking in the absence of fluid delivery and fluid receipt times for each tastant were incorporated into a general linear model to analyze fMRI data. By contrasting BOLD responses to sweet and sour tastes with those from distilled water, we identified taste responses in primary gustatory cortex area G, an adjacent portion of the anterior insular cortex, and area 12o. Choice tests run outside the scanner revealed that all three subjects strongly preferred sucrose over citric acid or water. BOLD responses in the ventral striatum and amygdala reflected subjects preferences, with greater BOLD responses to sucrose than citric acid. Finally, we examined the influence of hydration level by contrasting BOLD responses to receipt of fluids when animals were thirsty and after ad libitum water consumption. BOLD responses in area G and area 12o in the left hemisphere were greater following full hydration, which may reflect an influence of internal state on taste processing. By contrast, BOLD responses in portions of medial frontal cortex were reduced after ad libitum water consumption. Thus, activation in this region, which is implicated in value-based decision making, is modulated by internal state. These findings highlight brain regions involved in representing taste, taste preference and internal state.